1. Technical Field
Many aspects of this invention relate in general to proportional joystick speed controls for powered implements and, more particularly, to comprehensive systems and methods for providing an operator with feedback related to the actual speed of the object(s) being moved or the platform, bucket or the like that supports it. Some aspects of the invention also relate to the machines, systems, applications, components, and methods associated with such proportional speed controls.
2. Background Art
Powered implements can be found in a huge variety of applications, from forklifts, backhoes, excavators and off-highway construction equipment and the like to cherry-pickers and other boom lift movers, carriers or platforms. Many powered implements use proportional speed controls in the form of a joystick or an equivalent type of lever or knob that controls the actuators to do the powered moving. Actuators are often hydraulic but may also come in other forms such as electric, pneumatic, electro-magnetic, or some combination thereof. Even though the present invention is beneficial for many lever-based or knob-based variable speed controllers for virtually any powered lifters, boom lift platforms provide a representative context that will be referenced for the bulk of the descriptions in this application. Those of skill in the art will understand how the advantages and features in the boom lift platform context can be translated to other contexts within the scope of the inventions.
It takes an incredibly experienced boom lift operator to quickly yet precisely control the movement of an elevated platform to within an inch or so of the desired position without overshooting and correcting. Overshooting the intended position can be hazardous, particularly when that position is close to a structure that can be damaged if impacted by the boom-lift platform. Due in part to the nature of hydraulic actuators that are typically used for boom-lift platforms, there is a constant tension between responsive controls and smooth operation. Without sophisticated controls that are common today, platform movements can be very jerky.
On the other hand, because of the great effort to smooth out the movements of aerial platforms, it is very difficult to predict how much further a platform will travel before stopping once the joystick controller is released to the neutral position. The slow, gradual approach with fine movement control can be extremely time-consuming. In the interest of time, skilled operators therefore try to speed the platform toward the desired position and let go of the joystick a foot or two before the platform reaches the desired location, hoping they have predicted well enough to avoid a collision.
Joystick speed controls have long been one of the most popular types of manual devices for controlling speed. Numerous techniques are known for enhancing the basic joystick controller, as are evidenced by the following patents within the background art: U.S. Pat. Nos. 5,019,761; 5,513,100; 5,721,566; 5,727,387; 5,899,008; 6,859,198; and 7,019,238. Boom lift platforms and comparable position and/or speed controls are commercialized by JLG, Genie, Caterpillar, Case Corporation, John Deere, Bobcat, and Hitachi.
A sizable, unmet need has been revealed in relation to optimizing such movements, particularly in the interest of getting a boom lift platform to a desired position quickly yet safely. Related needs include the goal to minimize unnecessary cost and complexity, to enhance ease of use, and to shorten the training curve for safe boom lift operators. It is an object of the present invention to address these and other needs presented by the prior art. Other objects include enabling such primary objects while also allowing a highly skilled operator to override selectable features of preferred embodiments.
Known feedback technology helps, but more has long been needed. Overriding objects of the present inventions also include providing speed control systems, components and methods that facilitate and adjust, based on an accurate yet responsive position control system.